If a creature like this evolved, the pointed leg would simply be a specialized hoof. The point can and likely will be segmented, why? Because the spike hoof would just stab the ground, if anything it would have more traction. Since you want them to be bipedal, then keep in mind that they would need to stab the ground in order to stay up (that or have balancing mechanisms; see further down). The concept is similar to the Striders in Half-life but not tripodal.
This means that their environment has am easily stabbable ground layer. Your options here are;
- The Desert. A ground layer of sand would make loose and yet reliable area for the spike to pierce. Keep in mind that if you go with this solution, they would likely be nocturnal to avoid burning there feet on the hot sand.
- The Arctic. Similar in concept to the desert solution, the icy plains of the north would provide a stronger but harder to pierce ground.
- The Jungle. In a jungle, where there is a layer of decaying leaf litter, a creature like this would do well, although it would likely be a lot lighter. Think a spider monkey or a lemur.
A creature with spike hoofs would obviously have a big problem with running, even worse than humans. They would not be efficient runners, long or short distance and would never be able to jump.
That is if you're dead set on having there arms be human. If your willing, there are a plethora of solutions to help balance.
"Wings". Current theories on the velociraptor suggest that they may have used the feathers to balance themselves while hooked to prey. If these spike people human in a similar fashion, then their arms may evolve in a similar fashion.
Wings. remember the Pterosaur? its arms evolved into wings and its feet into weapons. In my question; Anatomically Correct Angels a similar solution was used. It's quite possible that angels may instead evolve their feet into harpoon like structures.
Beaks. While not exactly what you're looking for, a beak-like foot would solve the problem of balance. Going back to what I said about segmented spikes, if the spikes open into multiple fingers (like a beak), then it would use the spike for hunting and the open spike for walking. While this solution isn't the most accurate to your image, it gives the creature more open doors in mobility. such as more efficient long distance walking and even possibly jumping!